•Cr doped diamond like carbon (Cr-DLC) nanocomposite coatings were deposited by using a combined system.•The stress of the Cr-DLC coatings dramatically decreases from 0.98GPa to 0.49GPa as the Cr contents increases from 0at% to 9.7at%.•The results showed that Cr-DLC coating with low Cr concentration was a effective protective coating. Cr doped diamond like carbon (Cr-DLC) coatings were deposited by using a combined system consisting of middle frequency (MF) magnetron sputtering and ion plating. The structure and properties of the undoped and Cr-doped DLC coatings were analyzed by various testing, such as Raman, XPS, hardness and temperature-dependent frictional wear testing. The results showed that Cr-DLC coatings with low Cr concentration was a effective protective coating containing Cr–C nanometer grains, whose mechanical properties were obviously improved, such as, residual stress and cohesive strength, and still kept good wear resistance at the ambient temperature of 400°C.